The present invention relates to identification of one or more regions of interest in imaging procedures and, particularly, to identification of one or more regions of interest with a minimum of or without manual intervention and subsequent extraction of time value curves for the one or more regions of interest.
The following information is provided to assist the reader to understand the invention disclosed below and the environment in which it will typically be used. The terms used herein are not intended to be limited to any particular narrow interpretation unless clearly stated otherwise in this document. References set forth herein may facilitate understanding of the present invention or the background of the present invention. The disclosure of all references cited herein are incorporated by reference.
Image enhancement via injection of contrast enhancement media or contrast media in imaging procedures (for example, computed tomography or CT, magnetic resonance imaging or MRI, ultrasound imaging, etc.), is well known in the medical and imaging art. In general, a bolus of a contrast medium is injected intravenously and is carried by blood flow to one or more regions of interest (for example, an organ or blood vessel).
In a transit, timing or test bolus scan, a series of single-level or single-plane images are acquired at specified time intervals to determine how contrast propagates through a particular structure. In current practice, one or more regions of interest or ROIs are selected by manually drawing shapes on a single slice. Subsequently, average enhancement within each hand-drawn region of interest is computed for every slice in the time series, generating 1-D curves. FIG. 1A illustrates an example of a scan upon which two regions of interest corresponding to the trunk of the pulmonary artery (P) and the aorta (A) have been hand drawn. FIG. 1B illustrates a representative example of the time enhancement curves that are calculated from a transit, timing or test bolus performed as part of a cardiac Computed Tomography Angiogram or CTA procedure for the two regions of interest.
Accurate and consistent placement of regions of interest in the pulmonary artery and the aorta (and/or other region(s) of interest) is important to achieve desirable results. Accurate and consistent placement of the regions of interest is especially important if the time enhancement curves are to be used for optimization of a diagnostic protocol to be used in an imaging scan. Determining the size, shape, and location of the regions of interest is challenging and requires valuable operator time (for example, to go to a separate evaluation screen, to load the images, to draw the region(s) of interest, and to use the resulting data to generate and/or adjust the contrast/scan protocol).
In a number of procedures, sometimes referred to as tracking test bolus procedures, an operator is required to mark one or more regions of interest prior to contrast being injected. It can be particularly difficult to draw the regions of interest on the image before contrast has been injected. Moreover, factors such as patient movement can result in substantial inaccuracies.
It is desirable to develop improved devices, systems and/or methods for identifying, determining or defining regions of interest, particularly for extraction of time enhancement curves in imaging procedures.